<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>加载中loading效果</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            width: 100%;
            height: 100vh;
            background: #222;
            /* 实现子元素的垂直水平居中，采用Flex布局 */
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        .container {
            display: flex;
        }
        
        .container .point {
            width: 2em;
            height: 2em;
            border-radius: 50%;
            /* 实现圆形 */
            background: #fff;
            margin: 1em;
            user-select: none;
            position: relative;
        }
        
        .container .point::before {
            position: absolute;
            content: '';
            width: 100%;
            height: 100%;
            background: inherit;
            /* 从父元素继承背景颜色 */
            border-radius: inherit;
            /* 从父元素继承圆角 */
            animation: wave 2.2s ease-out infinite;
            /* 对before元素定义动画，完成时间2s, 采用ease-out过渡，重复循环 */
        }
        
        @keyframes wave {
            50%,
            70% {
                transform: scale(2.5);
            }
            80%,
            100% {
                opacity: 0;
            }
        }
        /* 设置背景颜色,自行选取五个颜色即可 */
        
        .container .point:nth-child(1) {
            background: #7ef9ff;
        }
        
        .container .point:nth-child(2) {
            background: #89cff0;
        }
        
        .container .point:nth-child(3) {
            background: #4682b4;
        }
        
        .container .point:nth-child(4) {
            background: #0f52ba;
        }
        
        .container .point:nth-child(5) {
            background: #000080;
        }
        /*
* 现在动画都是同时出现的，而我们需要的是一种逐渐出现的效果
* 所以需要对每个元素的动画加一个延迟
* 最后一个与第一个之间的间隔太短
* 所以需要把整体的动画时间延长一下
*/
        
        .container .point:nth-child(1)::before {
            animation-delay: 0s;
            /* 第一个不需要延迟 */
        }
        
        .container .point:nth-child(2)::before {
            animation-delay: 0.2s;
            /* 依次延迟0.2s */
        }
        
        .container .point:nth-child(3)::before {
            animation-delay: 0.4s;
        }
        
        .container .point:nth-child(4)::before {
            animation-delay: 0.6s;
        }
        
        .container .point:nth-child(5)::before {
            animation-delay: 0.8s;
        }
    </style>
</head>

<body>
    <div class="container">
        <div class="point"></div>
        <div class="point"></div>
        <div class="point"></div>
        <div class="point"></div>
        <div class="point"></div>
    </div>
</body>

</html>